Comparison of direct power control with hybrid approach on 3-Phase 4-wire active power filter between p-q-0 and p-q-r power theory

Abstract

New hybrid control approach of the pq control theory applied to the 3 phase 4 wire active power filter is proposed. This technique inherits not only the simplicity of the conventional direct power control but also offers a good dynamic response in active filtering. In this paper, the proposed control method is implemented for two different instantaneous power theories, i.e. p-q-0 and p-q-r power theory. The comparison between them is oriented around the harmonic contain of the source current for each method and the unbalanced current index. The analysis is verified using the PSIM simulation software. Index Terms -Hybrid control, direct power control, active power filter, power quality benchmarking.

Digital current control of a three‐phase four‐leg voltage source inverter by using p – q – r theory

“…The open-loop control block diagram corresponding to current control for each phase in three-phase four-leg VSI can be obtained as given in Fig. 6 by using (4), (6) and (13).…”

“…However, distortions such as phase-voltage unbalance and harmonics are usually present in power systems. The methods given in [1][2][3][4][5][6] are only accurate if voltages of power system are sinusoidal.…”

“…Spectral analysis is performed in frequency domain in [5] for one‐phase and three‐phase systems. Hybrid control approach is implemented for two different instantaneous power theories p – q –0 and p – q – r power theory in [6] for three‐phase four‐leg active power filter. Carrier‐based pulse width modulation (PWM) modulation and current control strategies for a four‐leg converter when it is particularly feeding a three‐phase load with imbalances in a – b – c reference frame are given in [7].…”

“…The instantaneous measurement theories given in [1–6] do not provide good performance if the power system voltages are unbalanced and/or distorted. However, distortions such as phase‐voltage unbalance and harmonics are usually present in power systems.…”

Discussions on the Instantaneous Reactive Power Theory Terms in the General Case Based on the Symmetric Components

“…The instantaneous powers defined by pq theory such as the real active power, the reactive imaginary power and the power along the γ axis have been presented in several references [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17], on the other hand the study of the voltages system and currents system imbalance effect on the different terms of these powers was also discussed where the symmetrical components were used. Unfortunately, these powers have not been clearly detailed.…”